聚乳酸/聚氧乙烯-聚氧丙烯醚嵌段共聚物共混体系的性能

采用熔融共混制备聚氧乙烯–聚氧丙烯醚嵌段共聚物增塑聚乳酸,研究聚氧乙烯–聚氧丙烯醚嵌段共聚物用量对聚乳酸/聚氧乙烯–聚氧丙烯醚嵌段共聚物共混体系流变性能、力学性能、热性能和微观结构的影响。当添加聚氧乙烯–聚氧丙烯醚嵌段共聚物的质量分数为20%时,聚乳酸/聚氧乙烯–聚氧丙烯醚嵌段共聚物共混体系的熔体流动速率为15.6g/(10min),比未增塑时提高约9倍,断裂伸长率为341.86%,撕裂强度为23.7N/cm,拉伸强度为44.5MPa,玻璃化转变温度从纯聚乳酸的60.1℃降到26.9℃。随着聚氧乙烯–聚氧丙烯醚嵌段共聚物用量的增加,共混体系的拉伸强度先下降后升高,断裂伸长率呈上升趋势,撕裂强度先下降后上升最后渐趋于稳定,聚乳酸链段的活动能力增强,增塑效果明显。扫描电子显微镜分析表明,当聚氧乙烯–聚氧丙烯醚嵌段共聚物质量分数≥12%时,共混体系脆冷断面的褶皱、粗糙度和裂纹明显增加,吸收能量能力增强,表现为断裂伸长率和撕裂强度提高。     

含聚氧化乙烯嵌段的二元多嵌段共聚物的合成和性能

用遥爪羟基聚苯乙烯与聚乙二醇和二氯甲烷在氢氧化钾存在下合成了氧亚甲基连接的聚氧乙烯－聚苯乙烯多嵌段共聚物，采用FT－IR、^1HNMR，分子量测定和凝胶渗透色谱分析表征共聚物的结构，研究了共聚物的乳化性能和相转移催化性能，结果表明，该类共聚物具有较好的乳化性能和相转移催化性能。     

含聚氧化乙烯嵌段的二元多嵌段共聚物的合成和性能

用遥爪羟基聚苯乙烯与聚乙二醇和二氯甲烷在氢氧化钾存在下合成了氧亚甲基连接的聚氧乙烯 -聚苯乙烯多嵌段共聚物 ,采用FT -IR、1HNMR、分子量测定和凝胶渗透色谱分析表征共聚物的结构 ,研究了共聚物的乳化性能和相转移催化性能。结果表明 ,该类共聚物具有较好的乳化性能和相转移催化性能     

PEO-PPO-PEO嵌段共聚物在水溶液中的自组装行为及其应用

聚氧乙烯-聚氧丙烯-聚氧乙烯(PEO-PPO-PEO)嵌段共聚物是一类重要的非离子表面活性剂,在选择性溶剂中可以自组装成多种形貌的介观结构。对PEO-PPO-PEO嵌段共聚物在水溶液中自组装行为进行了综述,介绍了其自组装行为的实验研究技术;阐明了嵌段共聚物构型、分子量、温度、浓度、添加剂等因素对PEO-PPO-PEO嵌段共聚物聚集行为的调控和作用机理;介绍了嵌段共聚物自组装特性的热力学模型、分子模拟及计算机预报等研究方法和研究进展;重点介绍了PEO-PPO-PEO嵌段共聚物在介孔材料制备、药物载体、生物大分子分离、嵌段共聚物修饰等方面的应用。     

水性涂料

正201604012聚碳酸酯/聚氧乙烯嵌段共聚物及其水性组合物的制备及应用:WO2015 170 374[国际专利申请,日]/日本:Asahi Kasei Chemicals Corporation(Miyazaki,Takayuki).-2015.11.12.-61页.-2014/JP62 270(2014.03.07)题述嵌段共聚物由聚碳酸酯链段和聚氧乙烯链段组成,且共聚物的端基为羟基。其中,聚碳酸酯链段的结构式为(ROCO_2)_m(R表示支化或非支化C_(2-15)脂肪烃、脂环烃、芳香烃;m表示数值);聚氧乙烯链段结构式为     

PEO-b-PS两亲性嵌段共聚物的合成与表征

以PEO-Br为大分子引发剂,CuBr/2-2’-联吡啶为催化体系,采用原子转移自由基聚合(ATRP)方法制得了一系列分子量可控且分子量分布窄的两亲性嵌段共聚物,通过1H-NMR、GPC、DSC等测试手段对其进行了表征,研究结果表明嵌段共聚物随着聚氧乙烯含量的降低,结晶度(Xc)、结晶熔融温度(Tm)、结晶温度(Tc)降低;当共聚物中聚氧乙烯的含量降为45%时,嵌段共聚物已无结晶现象。     

Pluronic-PEI纳米凝胶的制备

<正>聚氧乙烯-聚氧丙烯-聚氧乙烯是一类具有两亲性的三元嵌段共聚物,通常记为:EOx-POy-EOx,商品名为普朗尼克Pluronic,目前BASF公司已经对其实现了商业化生产。通过调节聚氧乙烯PEO和聚氧丙烯PPO的聚合度x、y的比值,可以生产出一系列性能各异的Pluronic产品,以适应不同的生产     

PA6─PEO二胺─BAPA嵌段共聚型抗静电剂共混改性涤纶的研究

在少量水存在下，将聚氧乙烯二胺（ＰＥＯ二胺）及Ｎ，Ｎ－二（３－氨丙基）甲胺（ＢＡＰＡ）与等摩尔的己二酸成盐后，再与己内酰胺共聚制得ＰＡ６－ＰＥＯ二胺－ＢＡＰＡ嵌段共聚物，然后将共聚物与ＰＥＴ切片进行共混熔融纺丝、拉伸，得到ＰＥＴ／ＰＡ６－ＰＥＯ二胺－ＢＡＰＡ共混改性纤维。研究发现，嵌段共聚物中低聚物含量少，改性纤维具有良好的可纺性、拉伸性及较高的强度保持值，共混纤维的抗静电性优良，还同时具有分散染料和酸性染料的可染性。对改性纤维进行季铵化处理后，可获得更加优越的抗静电效果。     

PO-EO-嵌段共聚物的结构剖析

本文阐述了PO-EO-嵌段共聚物(聚氧丙烯聚氧乙烯嵌段共聚)的结构剖析方法。其中包括化学分析法、色谱分析和光谱分析。采用核磁共振(NMR)可以简单而准确地确定PO-EO-嵌段共聚物的聚合度,根据聚合度可以求出平均分子量。同时,这些方法对指导生产和应用以及对未知同类产品的剖析具有重要的作用。     

Pluronic嵌段共聚物胶束作为靶向药物载体

聚氧乙烯 聚氧丙烯 聚氧乙烯 (PEO PPO PEO)三嵌段共聚物 (商品名为Pluronics)在水溶液中能自发生成多分子聚集的胶束 ,这些胶束主要以疏水的PPO嵌段为内核 ,PEO嵌段环绕在外构成外壳 ,这种胶束可以有效地增溶油溶性药物。Pluronic嵌段共聚物无毒、无刺激、无免疫原性 ,胶束外壳的PEO嵌段能阻止血小板的聚集。胶束尺寸和病毒相仿 ,其大小适合在体内传输。初步尝试表明 ,胶束表面嵌上合适的抗体可以将增溶了模型药物的Pluronic胶束定向输送到动物脑部 ,从而提高了药效 ,降低了副作用。实验表明 ,Pluronic嵌段共聚物胶束可能成为将多种药物导向特定部位的有效载体。     

Synthesis, characterization and properties of functional star and dendritic block copolymers of ethylene oxide and glycidol with oligoglycidol branching units

Well-defined, four-arm star block copolymers of ethylene oxide and glycidol were prepared via controlled anionic polymerization using protected glycidol. The length of the poly(ethylene oxide) block was varied from DP = 10 to 50, while the length of the short polyglycidol block remained nearly constant, at DP = 4-6. Star block copolymers with hydroxyl groups at the ends of the arms after conversion to the corresponding alkoxides were used as multifunctional macroinitiators for the sequential polymerization of ethylene oxide and protected glycidol. After deprotection, the branched block copolymers of ethylene oxide and glycidol had narrow molar mass distributions and multiple hydroxyl groups (up to 200) at the peripheries. The structure and functionality were determined using size exclusion chromatography with a light scattering detector and nuclear magnetic resonance spectroscopy. The thermal properties of the synthesized copolymers were also investigated, as well as the hydrophilic dye uptake to the hydrophobic phase containing copolymers.     

Anionic hydrotropes for industrial and institutional rinse aids

The effectiveness of eight commercial hydrotropes having differing structures (sodium xylenesulfonate, sodium-2-ethyl hexysulfate, phosphate ester of oxyethylated phenol, amine alkylaryl sulfonate, linear alkyl naphthalene sulfonate, TEA salt of DDBS, sodium dihexyl sulfosuccinate, and sodium dodecylbenzene sulfonate) was evaluated with seven commercial rinse aid surfactants of the following structural types: block copolymers and alcohol oxyalkylates with high and low levels of ethylene oxide. Two hydrotrope levels (3 and 6 wt %) were evaluated at two surfactant levels (20 and 40 wt %). Dispersibility, compatibility index, and blender foam heights were measured; the test methods are described.     

Novel non-ionic block copolymers tailored for interactions with phospholipids

The bulk of literature on phospholipid membrane interactions with non-ionic amphiphilic block copolymers deals with ABA triblock copolymers of poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide). This is partially the result of their commercial availability. In recent years novel block copolymers have been synthesized and their interactions with phospholipids structured as Langmuir monolayers, liposomes, bilayer lipid membranes, tethered bilayers, and living cells have been studied. This review describes some new block copolymers with potential to interact with phospholipids. There is a tremendous progress in synthesis of amphiphilic block copolymers triggered by new controlled polymerization techniques as atom transfer radical polymerization or nitroxide mediated polymerization and by the possibility to ‘click’ preformed blocks together using quantitative reactions of functional endgroups. A special focus is given to novel water soluble amphiphilic triblock copolymers of poly(glycerol monomethacrylate)-b-poly(propylene oxide)-b-poly(glycerol monomethacrylate) and their interactions with phosphatidylcholine lipids. Also block copolymers containing hydrophobic blocks with perfluoroalkyl groups are discussed since they are special in a sense that their fluorophilic blocks are neither hydrophilic nor oleophilic as this is the case for conventional amphiphilic block copolymers. Experimental methods to study block copolymer–phospholipid interactions are summarized and selected results based on special experimental techniques such as isothermal titration calorimetry, infrared reflection absorption spectroscopy and ion conductance are presented. This work is intended to convey a better quantitative understanding of amphiphilic block copolymers used for in vitro and in vivo experiments in medicine and pharmacy.     

The preparation of carbon nanotube/poly(ethylene oxide) composites using amphiphilic block copolymers

Polymer/multiwall carbon nanotube (MWCNT) composites were prepared by using amphiphilic block copolymers as dispersant. First, MWCNTs were wrapped with amphiphilic block copolymers in aqueous solution. Poly(ethylene oxide) was selected as the hydrophilic block because of its strong affinity with water while one of the following polymers: poly(ethylene), poly(butadiene), poly(styrene), poly(propylene oxide), or poly(thiophene) was used as the hydrophobic block of the copolymers. The dispersions were characterized by optical microscopy and transmission electron microscopy along with UV–Visible adsorption and dynamic light scattering. Based on the results, we could assess the effect on CNT dispersion quality of both, the molar mass of copolymers, the nature of the hydrophobic block and the length of hydrophilic block. The crystallization behavior of composites prepared from these dispersions was investigated. Results were related to the dispersion of the nanoparticles in the polymer matrix.     

Thermoplastic hydrogel based on pentablock copolymer consisting of poly(γ‐benzyl L‐glutamate) and poloxamer

A thermoplastic hydrogel based on a pentablock copolymer composed of poly(γ‐benzyl L ‐glutamate) (PBLG) and poloxamer was synthesized by polymerization of BLG N‐carboxyanhydride, which was initiated by diamine‐terminated groups located at the ends of poly(ethylene oxide) (PEO) chains of the poloxamer, to attain a new pH‐ and temperature‐sensitive hydrogel for drug delivery systems. Circular dichroism measurements in solution and IR measurements in the solid state revealed that the polypeptide block existed in the α‐helical conformation, as in the PBLG homopolymer. The intensity of the wide‐angle X‐ray diffraction patterns of the polymers depended on the poloxamer content in the copolymer and showed basically similar reflections to the PBLG homopolymer. The melting temperature (T_m) of the poloxamer in the copolymer was reduced with an increase of the PBLG block in comparison with the T_m of the poloxamer, which is indicative of a thermoplastic property. The water contents of the copolymers were dependent on the poloxamer content in the copolymers, for example, those for the GPG‐2 (48.7 mol % poloxamer) and GPG‐1 (57.5 mol % poloxamer) copolymers were 31 and 41 wt %, respectively, indicating characteristics of a polymeric hydrogel. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2649–2656, 2003     

Pluronic嵌段共聚物胶束化行为及其胶束增溶

两亲性质的Pluronic嵌段共聚物在合适条件下能自发形成内核很大的稳定胶束 ,其胶束化行为复杂 ,初步的研究深化了对两亲分子自组织机理的认识。实验发现这类胶束具有很强的增溶油溶性物质的能力 ,由于这些分子单体和胶束化行为的特点 ,可望利用这类嵌段共聚物实现在增溶应用场合中的突破。综述Pluronic嵌段共聚物的胶束化行为和胶束增溶规律的当前研究进展     

Surface properties of polymer films including multiblock copolymer

B(AB)_n multiblock copolymers of which the A block and the B block are hydrophobic and hydrophilic, respectively, were blended into crosslinkable coating compositions for preparing a hydrophilic surface, and compared with the graft copolymers including A and B as the pendant groups. The main constituent of A was polydimethyl-siloxane and that of B was poly(ethylene oxide). While the block copolymer slightly increased the hydrophobicity of the surface, it quickly became hydrophilic on contact with water. On the contrary, the graft copolymer increased the hydrophobicity even after its contact with water. Elementary analysis with ESCA demonstrated that both the silicon atoms and ether groups were concentrated on the very top of the surface in the films including the block copolymers but only silicon atoms were concentrated on the film surface which included the graft copolymers. In spite of their propensity to remain in the bulk due to their high surface energy, hydrophilic poly(ethylene oxide) moieties in the block copolymers migrated onto the near surface accompanying the movement of the hydrophobic polydimethyl-siloxane. because their mobility would be restricted by the bonding of both sides. Inclusion of the block copolymers significantly improved soil resistance. The advantage of the block copolymers as a surface modifier was further developed as an adhesion promoter. The introduction of a larger amount of the hydroxyl group into the hydrophilic block was effective for this purpose. This was discussed with respect to the change in the γ_p parameter.     

Temperature-sensitive biodegradable mixed star-shaped block copolymers hydrogels for an injection application

3-arm star-shaped poly(d,l-lactic-co-glycolic acid)-b-methoxy poly(ethylene glycol)(3sPLGA-mPEG) and 4sPLGA-mPEG copolymers are synthesized via the arm-first method. A facile method to obtain a temperature-sensitive physical injectable hydrogel is found using simply mixing two 4sPLGA-mPEG block copolymers aqueous solutions individually with thermogelling property (sol-gel-sol transition) or using simply mixing an aqueous sol of a 3sPLGA-mPEG block copolymer with a precipitate of a similar 3sPLGA-mPEG copolymer but with a varying PLGA/mPEG block ratio. A dramatic tuning of the sol–gel transition temperature is conveniently achieved by merely changing mix ratios. The degradation of mixed 3sPLGA-mPEG hydrogel proceeds by hydrolysis of ester bonds followed by the erosion of gel in PBS solution at body temperature for nearly 50 days. The mass loss and reduction of molecular weight are detected with increasing degradation time, and the mix ratios are found to slightly influence the degradation profiles. MTT assay and histological observations are used to examine the mixed copolymer solution. Both in vitro and in vivo results illustrate acceptable biocompatibility of our mixed materials. Collectively, our results show that the mixed star-shaped PLGA-mPEG block copolymer is a promising candidate as a novel injectable gel.     

Functionalized micelles from new ABC polyglycidol-poly(ethylene oxide)-poly(d,l-lactide) terpolymers

New ABC type terpolymers of poly(ethoxyethyl glycidyl ether)/poly(ethylene oxide)/poly(d,l-lactide) were obtained by multi-mode anionic polymerization. After successive deprotection of the ethoxyethyl groups from the first block, highly hydroxyl functionalized copolymers of polyglycidol/poly(ethylene oxide)/poly(d,l-lactide) were obtained. These copolymers form elongated ellipsoidal micelles by direct dissolution in water. The micelles consist of a poly(d,l-lactide) core and stabilizing shell of polyglycidol/poly(ethylene oxide). The hydroxyl groups of polyglycidol blocks situated at the micelle surface provide high functionality, which could be engaged in further chemical modification resulting in a potential drug targeting agents. The micellization process of the copolymers in aqueous media was studied by hydrophobic dye solubilization, static and dynamic light scattering, and transmission electron microscopy.